diff --git a/llmtools/tool_impl.py b/llmtools/tool_impl.py
index ee7e7e9..dfcd09e 100644
--- a/llmtools/tool_impl.py
+++ b/llmtools/tool_impl.py
@@ -34,7 +34,7 @@ def split_screen(split_n: Annotated[int, "要切换的分屏数量,整数并且
 
 
 @tool("play_video_record", description="播放、打开录像")
-def play_video_record(camera_name: Annotated[str, "相机名称,例如：南卡口1号相机"],
+def play_video_record(camera_name: Annotated[str, "相机名称,例如：南卡口1号相机,如果没有提供时间,结束时间为当前时间,开始时间为当前时间往前5分钟"],
                       start_time: Annotated[str, "录像开始时间,格式为yyyy-MM-dd hh:mm:ss，例 2025-03-16 01:00:00"],
                       end_time: Annotated[str, "录像结束时间,格式为yyyy-MM-dd hh:mm:ss，例 2025-03-16 02:09:31"]) -> str:
     log.info('【function】play_video_record 输入 [{},{},{}]', camera_name, start_time, end_time)